Progesterone is crucial for your menstrual cycle and fertility, but it also influences your sleep and your mood too.

A similar term you may have heard of, is progestin. This refers to the group of synthetic (chemically created) hormones that aim to mimic the progesterone produced in your body naturally. Progestins are commonly found in birth control medications. If you take the pill, use patches, have an implant, or get injections for contraception, these all contain progestins.

Common progestins used in contraception include norethindrone, norethindrone acetate, ethynodiol diacetate, levonorgestrel, norgestrel, desogestrel, norgestimate, medroxyprogesterone, etonogestrel, and drospirenone.

What does progesterone do?

Estrogen is the primary hormone during the first half of your menstrual cycle. However, once an egg is released and ovulation occurs, progesterone takes over for the second half of the month and helps to trigger your period, starting the next cycle.

Progesterone is especially important during pregnancy. It helps to develop the fetus and support your pregnancy as a whole.

When levels of progesterone run low it can cause:

  • Irregular periods and shorter menstrual cycles
  • Changes to your fertility
  • Heavy or irregular periods
  • Spotting
  • Premenstrual Syndrome (PMS)
  • Brain fog or fuzzy thinking
  • Sleep changes or difficulty sleeping
  • Mood changes and anxiety
  • Headaches and migraine attacks
  • Bloating or weight gain

Some physiological conditions affect how much progesterone you produce, these include:

  • Not ovulating. This is known as an anovulatory cycle and is common among those who have PCOS or are taking certain types of birth control. If this is the case, your progesterone levels will be lower during the luteal phase of your cycle.
  • Hypothyroidism or an underactive thyroid makes it more challenging for your body to produce the right amounts of progesterone.
  • Increased cortisol levels (aka the stress hormone) affects your progesterone levels).
  • Too much prolactin, (often due to a problem with the pituitary gland) can lead to low progesterone levels.
  • Low cholesterol levels. Interestingly, your body requires cholesterol in order to produce progesterone.

Your levels of natural progesterone can be increased by:

  • ensuring you get enough sleep
  • remaining active or taking part in regular exercise
  • eating nutritiously, ensuring the foods you consume contain enough zinc, magnesium, and vitamins B and C.

There are also a variety of options for treating low progesterone levels. There are creams, pills and pessaries (vaginal suppositories) that all contain progestins and can be used to help with symptoms you are experiencing. Discuss these with your doctor if you think you have low progesterone.

Sensitivity to progesterone or progestin

Many women notice a sensitivity to either their own natural progesterone levels, or more commonly, to the progestins contained in contraception medication. Progesterone is thought to be related to many of the PMS symptoms we experience. As levels are higher in the 2 weeks leading up to your period, this makes sense. For some women, this sensitivity can lead them to be diagnosed with a premenstrual disorder and symptoms can be very debilitating.

Known as progesterone intolerance, symptoms can include:


  • Anxiety
  • Irritability
  • Aggression
  • Panic attacks
  • Low mood
  • Forgetfulness


  • Acne
  • Cramping
  • Bloating
  • Fluid retention
  • Fatigue
  • Headaches & dizziness

More unusually, progesterone/progestins may affect systems that regulate your cholesterol, blood pressure and blood sugar levels.

If you think you may be suffering from low progesterone levels or be sensitive to the progestin in your contraception, discuss this with your doctor.